1. Field of the Invention
This invention relates in general to mechanisms for registering sheets in a travel path and more particularly to a self-compensating registration mechanism having a sheet registration gate which automatically adjusts to variations in the sheet travel path gap.
2. Description of the Prior Art
In certain types of high speed reproduction equipment, such as printing presses or electrophotographic copier/duplicators, information containing documents to be copied and/or pre-cut sheets of copy receiving material are fed seriatim in a travel path through the equipment in a predetermined operative cycle. In order to properly place an image of the document on the receiving material, the predetermined cycle typically requires registration of either the document or the receiving material (or both) at some point in their respective travel paths. One common mechanism for effecting such registration includes a retractable gate selectively blocking the travel path at a particular location; for example, see IBM Technical Disclosure Bulletin, Vol. 18, No. 10, p. 3199, or U.S. Pat. No. 3,937,454 (particularly FIG. 5).
Registration mechanisms having retractable gates provide satisfactory and reliable registration when used in conjunction with transport paths of fixed location relative to the mechanism. However, when the mechanism may vary in location relative to the transport path during operation, establishment and maintenance of gate adjustment has been difficult. Illustratively, when the travel path is defined by a gap between the registration mechanism and an opposed variably spaced guide, the gate may fail to completely span the gap between the mechanism and the guide and thus fail to block the path; or, the gate may be damaged or damage the guide if the travel of the gate is greater than the dimension of the gap.